Beam lead devices in which one or more semiconductor elements are formed on one surface of a semiconductor chip with leads for the circuits extending outwardly beyond the edges of the chip are desirable for many applications because of their reliability, packing density, heat dissipation capability and ability to operate over a wide range of temperatures and pressures. In order to reliably connect the beam leads to external circuitry, it has been found essential that the beam leads match the lead device to which they are connected in planarity to a tolerance preferably less than one thousandth of an inch. Otherwise, one or more of the beam leads will have stresses applied thereto, particularly when the chip is supported substantially entirely from the beam leads which results in either cracking at the edge of the semiconductor chip or failure of the bond to the lead.
Heretofore it has generally been necessary for reliable results to form a substrate of rigid material on which a pattern of leads was rigidly positioned with lead regions matching the positions of the beams of the semiconductor chip. The beam lead semiconductor device was then positioned with the beams contacting the lead pattern regions, and the beams were bonded to the lead pattern regions by a bonding system employing relatively low temperature and substantial pressure. Such a support with the lead pattern formed thereon, which was relatively expensive, could then be packaged with contacts made to a lead frame of the package, either by a plurality of wires each individually thermal compression bonded or by soldering a lead frame directly to the lead on the support. Such a dual step operation resulted in two or more bonds for each lead-out from each beam lead on the semiconductor chip, thereby increasing the probability of a bond failure.